LONDON:

PRINTED BY J. E. ADLARD,

BARTHOLOMEW CLOSE, E.C.

AS ONE OF THE EARLIEST AND MOST ACUTE OBSERVERS OF

PREFACE

TO THE

FIRST EDITION.

THE lectures which I herewith lay before the medical public at large were delivered in the early part of this year, in the new Pathological Institute of the University of Berlin, in the presence of a somewhat numerous assembly of medical men, for the most part physicians practising in the town. The object chiefly aimed at in them, illustrated as they were by as extensive a series of microscopical preparations as it was in my power to supply, was to furnish a clear and connected explanation of those facts upon which, according to my ideas, the theory of life must now be based, and out of which also the science of pathology has now to be constructed. They were more particularly intended as an attempt to offer in a better arranged form than had hitherto been done, a view of the cellular nature of all vital processes, both physiological and pathological, animal and vegetable, so as distinctly to set forth what even the people have long been dimly conscious of, namely, the unity of life in all organized beings, in opposition to the one-sided humoral and neuristical (solidistic) tendencies which have been transmitted from the mythical days of

1 See Lect. I, pp. 13-14, and Lect. XIV, pp. 284-286.-TRANS.

antiquity to our own times, and at the same time to contrast with the equally one-sided interpretations of a grossly mechanical and chemical bias-the more delicate mechanism and chemistry of the cell.

In consequence of the great advances that have been made in the details of science, it has been becoming continually more and more difficult to the majority of those who are engaged in practice, to obtain in the subjects treated on in these lectures that amount of personal experience which alone can guarantee a certain degree of accuracy of judgment. Day by day do those who are obliged to consume their best energies in the frequently so toilsome and so exhausting routine of practice find it becoming less and less possible for them, not only to closely examine, but even to understand the more recent medical works. For even the language of medicine is gradually assuming another appearance; well-known processes to which the prevailing system had assigned a certain place and name in the circle of our thoughts, change with the dissolution of the system their position and their denomination. When a certain action is transferred from the nerves, blood, or vessels to the tissues, when a passive process is recognized to be an active one, an exudation to be a proliferation, then it becomes absolutely necessary to choose other expressions whereby these actions, processes, and products shall be designated; and in proportion as our knowledge of the more delicate modes, in which the processes of life are carried on, becomes more perfect, just in that proportion must the new denominations also be adapted to this more delicate ground-work of our knowledge.

It would not be easy for any one to attempt to carry out the necessary reform in medical opinion with more respect for tradition than I have made it my endeavour to observe. Still my own experience has taught me that even in this there is a certain limit. Too great respect is a real fault, for it favours confusion; a well-selected expression renders at once accessible